Reset Firefox preferences to troubleshoot and fix problems

Resetting preferences (zoom, tabs, privacy, network, encryption, updates, where to save file downloads, etc.) is one of many procedures that can be helpful in troubleshooting Firefox problems. We'll explain two ways to do this.

Table of Contents

Solution 1: Reset Firefox to its default state

Note: When using the refresh feature, your bookmarks, browsing history, open tabs, windows, passwords, cookies and web form auto-fill information will be saved. However, your extensions and themes will be removed and your preferences will be reset.When using the reset feature, your bookmarks, browsing history, open tabs, windows, passwords, cookies and web form auto-fill information will be saved. However, your extensions and themes will be removed and your preferences will be reset.When using the reset feature, your bookmarks, browsing history, passwords, cookies and web form auto-fill information will be saved. However, your extensions and themes will be removed; open tabs, windows and tab groups will not be saved; and your preferences will be reset.Learn more.

At the top of the Firefox window, click the Help menu and select Troubleshooting Information.At the top of the Firefox window, click the Firefox button, go over to the Help sub-menu and select Troubleshooting Information.On the menu bar, click the Help menu and select Troubleshooting Information.

If you're unable to access the Help menu, type about:support in your address bar to bring up the Troubleshooting Information page.

Click the Reset Firefox… button in the upper-right corner of the Troubleshooting Information page.

To continue, click Reset Firefox in the confirmation window that opens.To continue, click Reset Firefox in the confirmation sheet that slides down.

Firefox will close and be reset. When it's done, a window will list the information that was imported. Click Finish and Firefox will open.Firefox will close and be reset. When it's done, a window will list the information that was imported. Click Done and Firefox will open.

Click the menu button
and then click help
.

From the Help menu choose Troubleshooting Information.

If you're unable to access the Help menu, type about:support in your address bar to bring up the Troubleshooting Information page.

Click the Reset Firefox… button in the upper-right corner of the Troubleshooting Information page.

To continue, click Reset Firefox in the confirmation window that opens.

Firefox will close and be reset. When it's done, a window will list the information that was imported. Click Finish and Firefox will open.

Click this Refresh Firefox button directly, if you are viewing this page in Firefox (it won't work if you are using a different browser). You will also find a Refresh button on the top right corner of the Firefox about:supportTroubleshooting Information page.

To continue, click Refresh Firefox in the confirmation window that opens.

Firefox will close to refresh itself. When finished, a window will list your imported information. Click Finish and Firefox will open.

Solution 1: Refresh Firefox

Note: When using the refresh feature, your bookmarks, browsing history, open tabs, windows, passwords, cookies and web form auto-fill information will be saved. However, your extensions and themes will be removed and your preferences will be reset.When using the reset feature, your bookmarks, browsing history, open tabs, windows, passwords, cookies and web form auto-fill information will be saved. However, your extensions and themes will be removed and your preferences will be reset.When using the reset feature, your bookmarks, browsing history, passwords, cookies and web form auto-fill information will be saved. However, your extensions and themes will be removed; open tabs, windows and tab groups will not be saved; and your preferences will be reset.Learn more.

At the top of the Firefox window, click the Help menu and select Troubleshooting Information.At the top of the Firefox window, click the Firefox button, go over to the Help sub-menu and select Troubleshooting Information.On the menu bar, click the Help menu and select Troubleshooting Information.

If you're unable to access the Help menu, type about:support in your address bar to bring up the Troubleshooting Information page.

Click the Reset Firefox… button in the upper-right corner of the Troubleshooting Information page.

To continue, click Reset Firefox in the confirmation window that opens.To continue, click Reset Firefox in the confirmation sheet that slides down.

Firefox will close and be reset. When it's done, a window will list the information that was imported. Click Finish and Firefox will open.Firefox will close and be reset. When it's done, a window will list the information that was imported. Click Done and Firefox will open.

Click the menu button
and then click help
.

From the Help menu choose Troubleshooting Information.

If you're unable to access the Help menu, type about:support in your address bar to bring up the Troubleshooting Information page.

Click the Reset Firefox… button in the upper-right corner of the Troubleshooting Information page.

To continue, click Reset Firefox in the confirmation window that opens.

Firefox will close and be reset. When it's done, a window will list the information that was imported. Click Finish and Firefox will open.

Click this Refresh Firefox button directly, if you are viewing this page in Firefox (it won't work if you are using a different browser). You will also find a Refresh button on the top right corner of the Firefox about:supportTroubleshooting Information page.

To continue, click Refresh Firefox in the confirmation window that opens.

Firefox will close to refresh itself. When finished, a window will list your imported information. Click Finish and Firefox will open.

Solution 2: Delete Firefox preference files

At the top of the Firefox window, click the Firefox button, go over to the Help menuOn the menu bar, click the Help menuAt the top of the Firefox window, click the Help menu and select Restart with Add-ons Disabled.... Firefox will start up with the Firefox Safe Mode dialog.

Note: You can also start Firefox in Safe Mode by holding down the shift key while starting Firefox.holding down the option key while starting Firefox.quitting Firefox and then going to your Terminal and running: firefox -safe-modeYou may need to specify the Firefox installation path (e.g. /usr/lib/firefox)

Click the menu button
, click help
and select Restart with Add-ons Disabled.... Firefox will start up with the Firefox Safe Mode dialog.

Note: You can also start Firefox in Safe Mode by holding down the shift key while starting Firefox.holding down the option key while starting Firefox.quitting Firefox and then going to your Terminal and running: firefox -safe-modeYou may need to specify the Firefox installation path (e.g. /usr/lib/firefox)

Click to put a check mark by Reset all user preferences to Firefox defaults.

To apply your changes, click Make Changes and Restart.

Firefox will restart with your preference settings changed back to the defaults.

At the top of the Firefox window, click on the Firefox button, go over to the Help menuOn the menu bar, click on the Help menuAt the top of the Firefox window, click on the Help menu and select Troubleshooting Information. The Troubleshooting Information tab will open.Click the menu button
, click help
and select Troubleshooting Information. The Troubleshooting Information tab will open.

Under the Application Basics section, click on Show FolderShow in FinderOpen Directory. A window with your profile filesfolder will open.

At the top of the Firefox window, click on the Firefox button and then select ExitAt the top of the Firefox window, click on the File menu and then select ExitOn the menu bar, click on the Firefox menu and select Quit FirefoxAt the top of the Firefox window, click on the File menu and select Quit

Click the menu button
and then click ExitQuit

Locate and delete the file prefs.js (or rename it, for example, to prefs.jsOLD, to keep the old file as a backup). If you find more than one, a prefs.js.moztmp file or a user.js file, delete (or rename) these as well.